This invention relates to an engine driven hand-operated tool, especially a motor or a chain saw, with at least one handle which is configured hollow, and with a driving engine, especially an internal combustion engine or an electric motor and a fluid cooling with a cooling fluid flow being provided for driving engine.
When working longer with an engine driven hand-operated tool which transfers high vibrations to a handle, it can come in dependence on these vibrations to circulatory disturbances in the hands of the operator who holds the hand-operated tool with the handle. This illness is also known as ischemic fingers illness. Such circumstances appear especially when using motor or chain saws, whereby low temperatures still reinforce this effect. Therefore, chain saws with an electric handle heating have already been constructed and marketed. However, because of the very low number of items produced, these chain saws are relatively expensive, have high production costs and high development costs, and all machines of a construction kit of the same type, even those without handle heating, must be provided with the necessary construction sparings for the components of the electrical heating, such as generator, cabling and switches, which means for the user without handle separation unnecessary construction width and weight, as well as disadvantages when handling.
The aim of this invention is to make available an improved hand-operated tool of the above mentioned type which eliminates the above mentioned disadvantages and thus prevents, at low temperatures, the risk of permanent impairments due to circulatory disturbances in the hands of an operator.
To this purpose, it is provided for according to the invention that the handle shows at least one inlet opening and at least one outlet opening, whereby the inlet opening and the outlet opening are placed in such a way that the cooling fluid flow downstream of the driving engine flows into the handle over the inlet opening, flows through the handle over a predetermined section and flows out of the handle again by the outlet opening.
This has the advantage that a handle heating is realized at low cost and without additional construction space required, whereby additional devices such as, for example, a generator, a cabling or a switch are not necessary. Each engine driven hand-operated tool can also be equipped later with this handle heating according to the invention simply and at low cost.
In a preferred embodiment, the fluid cooling is an air cooling and the cooling fluid flow a cooling air flow.
A simple and low cost assembly is obtained by the fact that an air conducting device fixed on the handle adjacent to the inlet opening is placed and configured in the cooling air flow downstream of the driving engine in such a way that the cooling air flow is at least partially intercepted by the air conducting device and is guided into the inlet opening on the handle. This air conducting device is configured, for example, as an air conducting sheet and is fixed or pushed-on or snapped-on onto the handle.
In an alternative preferred embodiment, the fluid cooling is a water cooling and the cooling fluid flow a cooling water flow.
A simple power regulation of the handle heating or of a temperature on the handle is obtained by the fact that a first slide is provided for the alternative opening, partial opening or closing selectively the inlet opening and/or a second slide for the opening, partialy partiality opening or closing the oulet opening.
In an appropriate manner, the handle is a stirrup-shaped handle or an allround handle and is configured, for example, as a metal tube or is made of plastic.
In a preferred embodiment, a device for guiding the cooling air flow downstream of the driving engine to the inlet opening is configured integrated into a tank/handle system.
The invention will be explained in more detail below with reference to the attached drawings.